Mechanical Turk ExternalQuestion pointers

1) If you are going to use an ExternalQuestion with Mechanical Turk command line API, you will need to use the following in your .question file:

<?xml version="1.0" encoding="UTF-8"?>
<ExternalQuestion xmlns="http://mechanicalturk.amazonaws.com/AWSMechanicalTurkDataSchemas/2006-07-14/ExternalQuestion.xsd">
  <ExternalURL>http://myexternalquestion.html</ExternalURL>
  <FrameHeight>400</FrameHeight>
</ExternalQuestion>

2) The form action for the Sandbox is "https://workersandbox.mturk.com/mturk/externalSubmit"